Metal coordination compound, luminescence device and display apparatus

ABSTRACT

An electroluminescence device having a layer containing a specific metal coordination compound is provided. The metal coordination compound is represented by formula (1) below:
 
ML m L′ n   (1),
 
wherein M is a metal atom of Ir, Pt, Rh or Pd; L and L′ are mutually different bidentate ligands; m is 1, 2 or 3 and n is 0, 1 or 2 with the proviso that m+n is 2 or 3; a partial structure MLm is represented by formula (2) shown below and a partial structure ML′ n  is represented by formula (3) or (4) shown below:  
                 
 
at least one of the optional substituent(s) of the cyclic groups, and the cyclic groups CyCl and CyC2 includes a benzofuran structure capable of having a substituent represented by the following formula (5):  
                 
The metal coordination compound having the benzofuran structure is effective in providing high-efficiency luminescence and long-term high luminance.

FIELD OF THE INVENTION AND RELATED ART

The present invention relates to an organic luminescence device (alsocalled an organic electroluminescence device or organic EL device) foruse in a planar light source, a planar display, etc. Particularly, thepresent invention relates to a novel metal coordination compound and aluminescence device having a high luminescence efficiency and causinglittle change with time by using a metal coordination compoundrepresented by formula (1) appearing hereinafter.

An old example of organic luminescence device is, e.g., one usingluminescence of a vacuum-deposited anthracene film (Thin Solid Films, 94(1982) 171). In recent years, however, in view of advantages, such aseasiness of providing a large-area device compared with an inorganicluminescence device, and possibility of realizing desired luminescencecolors by development of various new materials and drivability at lowvoltages, an extensive study thereon for device formation as aluminescence device of a high-speed responsiveness and a highefficiency, has been conducted.

As precisely described in Macromol. Symp. 125, 1-48 (1997), for example,an organic EL device generally has an organization comprising a pair ofupper and lower electrodes formed on a transparent substrate, andorganic material layers including a luminescence layer disposed betweenthe electrodes.

In the luminescence layer, aluminum quinolinol complexes (inclusive ofAlq3 shown hereinafter as a representative example) having anelectron-transporting characteristic and a luminescence characteristic,are used for example. In a hole-transporting layer, a material having anelectron-donative property, such as a triphenyldiamine derivative(inclusive of α-NPD shown hereinafter as a representative example), isused for example.

Such a device shows a current-rectifying characteristic such that whenan electric field is applied between the electrodes, holes are injectedfrom the anode and electrons are injected from the cathode.

The injected holes and electrons are recombined in the luminescencelayer to form excitons, which emit luminescence when they aretransitioned to the ground state.

In this process, the excited states include a singlet state and atriplet state and a transition from the former to the ground state iscalled fluorescence and a transition from the latter is calledphosphorescence. Materials in theses states are called singlet excitonsand triplet excitons, respectively.

In most of the organic luminescence devices studied heretofore,fluorescence caused by the transition of a singlet exciton to the groundstate, has been utilized. On the other hand, in recent years, devicesutilizing phosphorescence via triplet excitons have been studied.

Representative published literature may include:

-   Article 1: Improved energy transfer in electrophosphorescent device    (D. F. O'Brien, et al., Applied Physics Letters, Vol. 74, No. 3, p.    422 (1999)); and-   Article 2: Very high-efficiency green organic light-emitting devices    based on electrophosphorescence (M. A. Baldo, et al., Applied    Physics Letters, Vol. 75, No. 1, p. 4 (1999)).

In these articles, a structure including four organic layers sandwichedbetween the electrodes, and the materials used therein includecarrier-transporting materials and phosphorescent materials, of whichthe names and structures are shown below together with theirabbreviations.

-   Alq3: aluminum quinolinol complex-   α-NPD:    N4,N4′-di-naphthalene-1-yl-N4,N4′-diphenyl-biphenyl-4,4′-diamine-   CBP: 4,4′-N,N′-dicarbazole-biphenyl-   BCP: 2,9-dimethyl-4,7-diphenyl-1, 10-phenanthroline-   PtOEP: platinum-octaethylporphyrin complex-   Ir(ppy)₃: iridium-phenylpyrimidine complex

The above-mentioned Articles 1 and 2 both have reported structures, asexhibiting a high efficiency, including a hole-transporting layercomprising α-NPD, an electron-transporting layer comprising Alq3, anexciton diffusion-preventing layer comprising BCP, and a luminescencelayer comprising CBP as a host and ca. 6% of PtOEP or Ir(ppy)₃ as aphosphorescent material dispersed in mixture therein.

Such a phosphorescent material is particularly noted at present becauseit is expected to provide a high luminescence efficiency in principlefor the following reasons. More specifically, excitons formed by carrierrecombination comprise singlet excitons and triplet excitons in aprobability ratio of 1:3. Conventional organic EL devices have utilizedfluorescence of which the luminescence efficiency is limited to at most25%. On the other hand, if phosphorescence generated from tripletexcitons is utilized, an efficiency of at least three times is expected,and even an efficiency of 100%, i.e., four times, can be expected inprinciple, if a transition owing to intersystem crossing from a singletstate having a higher energy to a triplet state is taken into account.

However, like a fluorescent-type device, such an organic luminescencedevice utilizing phosphorescence is generally required to be furtherimproved regarding the deterioration of luminescence efficiency anddevice stability.

The reason of the deterioration has not been fully clarified, but thepresent inventors consider as follows based on the mechanism ofphosphorescence.

In the case where the luminescence layer comprises a host materialhaving a carrier-transporting function and a phosphorescent guestmaterial, a process of phosphorescence via triplet excitons may includeunit processes as follows:

-   1. transportation of electrons and holes within a luminescence    layer,-   2. formation of host excitons,-   3. excitation energy transfer between host molecules,-   4. excitation energy transfer from the host to the guest,-   5. formation of guest triplet excitons, and-   6. transition of the guest triplet excitons to the ground state and    phosphorescence.

Desirable energy transfer in each unit process and luminescence arecaused in competition with various energy deactivation processes.

Needless to say, a luminescence efficiency of an organic luminescencedevice is increased by increasing the luminescence quantum yield of aluminescence center material.

Particularly, in a phosphorescent material, this may be attributable toa life of the triplet excitons which is longer by three or more digitsthan the life of a singlet exciton. More specifically, because it isheld in a high-energy excited state for a longer period, it is liable toreact with surrounding materials and cause polymer formation among theexcitons, thus incurring a higher probability of deactivation processresulting in a material change or life deterioration.

A luminescence device is desired to exhibit high efficiency luminescenceand show a high stability. Particularly, it is strongly desired toprovide a luminescence material compound which is less liable to causeenergy deactivation in a long life of excited energy state and is alsochemically stable, thus providing a longer device life.

SUMMARY OF THE INVENTION

Accordingly, principal objects of the present invention are to provide aluminescence material which exhibits a high luminescence efficiency andretains a high luminance for a long period, and also provide aluminescence device and a display apparatus using the same.

In the present invention, a metal complex is used as a luminescencematerial, particularly a novel luminescent metal complex compoundcomprising iridium as a center metal and a benzofuran structure offormula (5) appearing hereinafter as a part of a ligand or as asubstituent of a ligand.

More specifically, the present invention provides as a luminescencematerial a metal coordination compound represented by formula (1) below:ML_(m)L′_(n)  (1),wherein M is a metal atom of Ir, Pt, Rh or Pd; L and L′ are mutuallydifferent bidentate ligands; m is 1, 2 or 3 and n is 0, 1 or 2 with theproviso that m+n is 2 or 3; a partial structure MLm is represented byformula (2) shown below and a partial structure ML_(n) is represented byformula (3) or (4) shown below:

wherein CyN1 and CyN2 are each cyclic group capable of having asubstituent, including a nitrogen atom and bonded to the metal atom Mvia the nitrogen atom; CyC1 and CyC2 are each cyclic group capable ofhaving a substituent, including a carbon atom and bonded to the metalatom M via the carbon atom with the proviso that the cyclic group CyN1and the cyclic group CyC1 are bonded to each other via a covalent bondand the cyclic group CyN2 and the cyclic group CyC2 are bonded to eachother via a covalent bond;

the optional substituent of the cyclic groups is selected from a halogenatom, cyano group, a nitro group, a trialkylsilyl group of which thealkyl groups are independently a linear or branched alkyl group having 1to 8 carbon atoms, a linear or branched alkyl group having 1 to 20carbon atoms of which the alkyl group can include one or non-neighboringtwo or more methylene groups that can be replaced with —O—, —S—, —CO—,—CO—O—, —O—CO—, —CH═CH— or —C≡C—, and the alkyl group can include ahydrogen atom that can be optionally replaced with a fluorine atom, oran aromatic group capable of having a substituent (that is a halogenatom, a cyano atom, a nitro atom, a linear or branched alkyl grouphaving 1 to 20 carbon atoms of which the alkyl group can include one ornon-neighboring two or more methylene groups that can be replaced with—O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C—, and the alkyl groupcan include a hydrogen atom that can be optionally replaced with afluorine atom);

E and G are independently a linear or branched alkyl group having 1 to20 carbon atoms of which the alkyl group can include a hydrogen atomthat can be optionally replaced with a fluorine atom, or an aromaticgroup capable of having a substituent (that is a halogen atom, a cyanoatom, a nitro atom, a trialkylsilyl group of which the alkyl groups areindependently a linear or branched alkyl group having 1-8 carbon atoms,a linear or branched alkyl group having 1 to 20 carbon atoms of whichthe alkyl group can include one or non-neighboring two or more methylenegroups that can be replaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH—or —C≡C—, and the alkyl group can include a hydrogen atom that can beoptionally replaced with a fluorine atom; and

at least one of the optional substituent(s) of the cyclic groups, andthe cyclic groups CyC1 and CyC2 includes a benzofuran structure capableof having a substituent represented by the following formula (5):

wherein the benzofuran structure of the formula (5) is bonded to CyN1,CyN2, CyC1 or CyC2 via a single bond at any one of 2- to 7-positionswhen the benzofuran structure is the optional substituent(s) of thecyclic groups, and the benzofuran structure of the formula (5) is bondedto CyN1 or CyN2 via a single bond at any one of 2- to 7-positions andbonded to the metal atom M via a single bond at any one of 2- to7-positions when the benzofuran structure is CyC1 or CyC2;

the optional substituent of the benzofuran structure of the formula (5)is selected from a halogen atom, cyano group, a nitro group, atrialkylsilyl group of which the alkyl groups are independently a linearor branched alkyl group having 1 to 8 carbon atoms, a linear or branchedalkyl group having 1 to 20 carbon atoms of which the alkyl group caninclude one or non-neighboring two or more methylene groups that can bereplaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C—, and thealkyl group can include a hydrogen atom that can be optionally replacedwith a fluorine atom, or an aromatic group capable of having asubstituent (that is a halogen atom, a cyano atom, a nitro atom, alinear or branched alkyl group having 1 to 20 carbon atoms of which thealkyl group can include one or non-neighboring two or more methylenegroups that can be replaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH—or —C≡C—, and the alkyl group can include a hydrogen atom that can beoptionally replaced with a fluorine atom) with the proviso that anadjacent pair of substituents located at 4- to 7-positions of thebenzofuran structure of the formula (5) can be bonded to form a cyclicstructure.

Preferred embodiments of the metal coordination compound of the formula(1) according to the present invention include the following:

A metal coordination compound, wherein n is 0 in the formula (1).

A metal coordination compound having a partial structure ML′_(n)represented by the formula (3) in the formula (1).

A metal coordination compound having a partial structure ML′_(n)represented by the formula (4) in the formula (1).

A metal coordination compound wherein the cyclic groups CyC1 in theformula (1) and CyC2 in the formula (3) are independently selected fromphenyl group, thienyl group, thianaphthyl group, naphthyl group, pyrenylgroup, 9-fluorenonyl group, fluorenyl group, dibenzofuranyl group,dibenzothienyl group, carbazolyl group, or benzofuranyl group, as anaromatic cyclic group capable of having a substituent with the provisothat the aromatic cyclic group can include one or two CH groups that canbe replaced with a nitrogen atom, particularly selected from phenylgroup or benzofuranyl group.

A metal coordination compound, wherein the cyclic groups CyN1 in theformula (2) and CyN2 in the formula (3) are independently selected frompyridyl group, pyridazinyl group, and pyrimidinyl group, particularlypyridyl group, as an aromatic cyclic group capable of having asubstituent.

A metal coordination compound, wherein the cyclic groups CyN1, CyN2,CyC1 and CyC2 are independently non-substituted, or have a substituentselected from a halogen atom and a linear or branched alkyl group having1 to 20 carbon atoms {of which the alkyl group can include one ornon-neighboring two or more methylene groups that can be replaced with—O—, —S—, —CO—, —CH═CH—, —C≡C—, or a divalent aromatic group capable ofhaving a substituent (that is a halogen atom or a linear or branchedalkyl group having 1 to 20 carbon atoms (of which the alkyl group caninclude one or non-neighboring two or more methylene groups that can bereplaced with —O—, and the alkyl group can include a hydrogen atom thatcan be optionally replaced with a fluorine atom)), and the alkyl groupcan include a hydrogen atom that can be optionally replaced with afluorine atom}.

A metal coordination compound, wherein M in the formula (1) is iridium.

A metal coordination compound represented by the following formula (6)or (7), particularly the formula (7):

wherein R₁, R₂, R₃, R′₃ and R₄ are independently

a hydrogen atom; a fluorine atom; a linear or branched alkyl group offormula: C_(n)H_(2n+1)— in which n is an integer of 1-20, the alkylgroup can include one or non-neighboring two or more methylene groupsthat can be replaced with —O— and also can include a hydrogen atom thatcan be optionally replaced with a fluorine atom; a phenyl group capableof having a substituent; or a benzofuranyl group capable of having asubstituent; the optional substituent of phenyl group and benzofuranylgroup is a fluorine atom or a linear or branched alkyl group of formula:C_(n)H_(2n+1) — in which n is an integer of 1-20, the alkyl group caninclude one or non-neighboring two or more methylene groups that can bereplaced with —O— and also can include a hydrogen atom that can beoptionally replaced with a fluorine atom.

The present invention also provides an electroluminescence device,comprising: a pair of electrodes disposed on a substrate, and aluminescence unit comprising at least one organic compound disposedbetween the electrodes, wherein the organic compound comprises a metalcoordination compound represented by the formula (1) described above.

In the luminescence device, a voltage is applied between the electrodesto emit phosphorescence.

The present invention further provides a picture display apparatus,comprising an electroluminescence device described above and a means forsupplying electric signals to the electroluminescence device.

These and other objects, features and advantages of the presentinvention will become more apparent upon a consideration of thefollowing description of the preferred embodiments of the presentinvention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B and 1C illustrate embodiments of the luminescence deviceaccording to the present invention, respectively.

FIG. 2 schematically illustrates a panel structure including an ELdevice and drive means.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Basic structures of organic luminescence (EL) devices formed accordingto the present invention are illustrated in FIGS. 1A, 1B and 1C.

As shown in these figures, an organic luminescence device generallycomprises, on a transparent substrate 15, a 50 to 200 nm-thicktransparent electrode 14, a plurality of organic film layers and a metalelectrode 11 formed so as to cover the organic layers.

FIG. 1A shows an embodiment wherein the organic luminescence devicecomprises a luminescence layer 12 and a hole-transporting layer 13. Thetransparent electrode 14 may comprise ITO, etc., having a large workfunction so as to facilitate hole injection from the transparentelectrode 14 to the hole-transporting layer 13. The metal electrode 11comprises a metal material having a small work function, such asaluminum, magnesium or alloys of these elements, so as to facilitateelectron injection into the organic luminescence device.

The luminescence layer 12 comprises a compound (metal coordinationcompound) according to the present invention. The hole-transportinglayer 13 may comprise, e.g., a triphenyldiamine derivative, asrepresented by α-NPD mentioned above, and also a material having anelectron-donative property as desired.

A device organized above exhibits a current-rectifying characteristic,and when an electric field is applied between the metal electrode 11 asa cathode and the transparent electrode 14 as an anode, electrons areinjected from the metal electrode 11 into the luminescence layer 12, andholes are injected from the transparent electrode 15. The injected holesand electrons are recombined in the luminescence layer 12 to formexcitons having high energy potential, which cause luminescence duringtransition to the ground state. In this instance, the hole-transportinglayer 13 functions as an electron-blocking layer to increase therecombination efficiency at the boundary between the luminescence layerlayer 12 and the hole-transporting layer 13, thereby providing anenhanced luminescence efficiency.

Further, in the structure of FIG. 1B, an electron-transporting layer 16is disposed between the metal electrode 11 and the luminescence layer 12in FIG. 1A. As a result, the luminescence function is separated from thefunctions of electron transportation and hole transportation to providea structure exhibiting more effective carrier blocking, thus increasingthe luminescence efficiency. The electron-transporting layer 16, maycomprise, e.g., an oxadiazole derivative.

FIG. 1C shows another desirable form of a four-layer structure,including a hole-transporting layer 13, a luminescence layer 12, anexciton diffusion prevention layer 17 and an electron-transporting layer16, successively from the side of the transparent electrode 14 as theanode.

The luminescence materials used in the present invention are mostsuitably metal coordination compounds represented by the above-mentionedformulae (1) to (5), which are found to cause high-efficiencyluminescence, retain high luminance for a long period and show littledeterioration by current passage.

The metal coordination compound of the present invention emitsphosphorescence, and its lowest excited state is believed to be an MLCT*(metal-to-ligand charge transfer) excited state or π-π* excited state ina triplet state, and phosphorescence is caused at the time of transitionfrom such a state to the ground state.

Hereinbelow, methods for measurement of some properties and physicalvalues described herein for characterizing the luminescence material ofthe present invention will be described.

(1) Judgment Between Phosphorescence and Fluorescence

The identification of phosphorescence was effected depending on whetherdeactivation with oxygen was caused or not. A solution of a samplecompound in chloroform after aeration with oxygen or with nitrogen issubjected to photoillumination to cause photo-luminescence. Theluminescence is judged to be phosphorescence if almost no luminescenceattributable to the compound is observed with respect to the solutionaerated with oxygen but photo-luminescence is confirmed with respect tothe solution aerated with nitrogen. The phosphorescence of all thecompounds of the present invention has been confirmed by this methodunless otherwise noted specifically.

(2) Phosphorescence yield (a relative quantum yield, i.e., a ratio of anobjective sample's quantum yield

(sample) to a standard sample's quantum yield

(st)) is determined according to the following formula:

(sample)/

(st)=[Sem(sample)/Iabs(sample)]/[Sem(st)/Iabs(st)],wherein Iabs(st) denotes an absorption coefficient at an excitationwavelength of the standard sample; Sem(st), a luminescence spectralareal intensity when excited at the same wavelength; Iabs(sample), anabsorption coefficient at an excitation wavelength of an objectivecompound; and Sem(sample), a luminescence spectral areal intensity whenexcited at the same wavelength.

Phosphorescence yield values described herein are relative values withrespect to a phosphorescence yield

=1 of Ir(ppy)₃ as a standard sample.

(3) A Method of Measurement of Phosphorescence Life is as Follows.

A sample compound is dissolved in chloroform and spin-coated onto aquartz substrate in a thickness of ca. 0.1 μm and is exposed topulsative nitrogen laser light at an excitation wavelength of 337 nm atroom temperature by using a luminescence life meter (made by HamamatsuPhotonics K.K.). After completion of the excitation pulses, the decaycharacteristic of luminescence intensity is measured.

When an initial luminescence intensity is denoted by I₀, a luminescenceintensity after t(sec) is expressed according to the following formulawith reference to a luminescence life z(sec):I=I ₀·exp(−t/τ).

The luminescence material (metal coordination compound) of the presentinvention exhibited high phosphorescence quantum yields of 0.11 to 0.9and short phosphorescence lives of 0.1 to 40 μsec. A shortphosphorescence life becomes a condition for causing little energydeactivation and exhibiting an enhanced luminescence efficiency. Morespecifically if the phosphorescence life is long, the number of tripletstate molecules maintained for luminescence is increased, and thedeactivation process is liable to occur, thus resulting in a lowerluminescence efficiency particularly at the time of a high-currentdensity. The material of the present invention has a relatively shortphosphorescence life thus exhibiting a high phosphorescence quantumyield, and is therefore suitable as a luminescence material for an ELdevice.

As a result of various studies of ours, it has been found that anorganic EL device using the metal coordination compound of the formula(1) as a principal luminescence material causes high-efficiencyluminescence, retains high luminance for a long period and shows littledeterioration by current passage.

In the formula (1) representing the metal coordination compound of thepresent invention, n may preferably 0 or 1, more preferably 0. Further,the partial structure ML'n may preferably comprise the benzofuranstructure represented by the above-mentioned formula (5).

In the present invention, by incorporating the benzofuran structure ofthe formula (5) into the metal coordination compound of the formula (1),it becomes possible to control an emission wave-length (particularly toprovide a long emission wavelength). The presence of the benzofuranstructure of the formula (5) is effective in enhancing a solubility ofthe metal coordination compound of the present invention in an organicsolvent, thus facilitating a purification thereof by recrystallizationor column chromatography. As a result, the metal coordination compoundof the present invention is suitable as a luminescence material for theorganic EL device.

Further, as shown in Examples appearing hereinafter, it has beensubstantiated that the metal coordination compound of the presentinvention exhibited an excellent stability in a continuous currentpassage test. This may be attributable to incorporation of thebenzofuran structure of the formula (5) into the molecular structure ofthe metal coordination compound of the formula (1) according to thepresent invention. More specifically, a change in intermolecularinteraction due to the introduction of the benzofuran structure of theformula (5) allows an intermolecular interact-ion of the metalcoordination compound with, e.g., a host material to suppress formationof exciton associates-causing thermal deactivation, thus reducing aquenching process thereby to improve phosphorescence yield and devicecharacteristics.

In the case where CyN1 (or CyN2) is benzofranyl group and CyC1 (or CyC2)is pyridyl or pyrimidinyl group in the metal coordination compound offormula (1) of the present invention, pyridyl or pyrimidinyl group (CyC1or CyC2) may preferably have a substituent other than methyl group,methoxy group, butyl group and fluorine atom when benzofuran group (CyN1or CyN2) is not substituted. In another preferred embodiment in theabove case, benzofuran group (CyN1 or CyN2) has a substituent,particularly trifluoromethyl group or an aromatic group. In stillanother preferred embodiment in the above case, the metal coordinationcompound has a substituent such as trifluoromethyl group, an aromaticgroup or a cyclized group (e.g., —(CH═CH)₂—).

The luminescence device according to the present invention maypreferably be an electroluminescence device of the type wherein a layerof the metal coordination compound of the formula (1) is disposedbetween opposing two electrodes and a voltage is applied between theelectrodes to cause luminescence, particularly phosphorescence, as shownin FIGS. 1A, 1B and 1C.

The luminescence device according to the present invention may beapplicable to devices required to allow energy saving and highluminance, such as those for display apparatus and illuminationapparatus, a light source for printers, and backlight (unit) for aliquid crystal display apparatus. Specifically, in the case of using theluminescence device of the present invention in the display apparatus,it is possible to provide a flat panel display apparatus capable ofexhibiting an excellent energy saving performance, a high visibility anda good lightweight property.

For the application to a display, a drive system using a thin-filmtransistor (TFT) drive circuit according to an active matrix-scheme maybe used. Hereinbelow, an embodiment of using a device of the presentinvention in combination with an active matrix substrate is brieflydescribed with reference to FIG. 2.

FIG. 2 illustrates an embodiment of panel structure comprising an ELdevice and drive means. The panel is provided with a scanning signaldriver, a data signal driver and a current supply source which areconnected to gate selection lines, data signal lines and current supplylines, respectively. At each intersection of the gate selection linesand the data signal lines, a display pixel electrode is disposed. Thescanning signal drive sequentially selects the gate selection lines G1,G2, G3 . . . Gn, and in synchronism herewith, picture signals aresupplied from the data signal driver to display a picture (image).

By driving a display panel including a luminescence layer comprising aluminescence material of the present invention, it becomes possible toprovide a display which exhibits a good picture quality and is stableeven for a long period display.

Some synthetic paths for providing a metal coordination compoundrepresented by the above-mentioned formula (1) are illustrated belowwith reference to an iridium coordination compound (m+n=3) for example:

Other metal coordination compound (M=Pt, Rh and Pd) can also besynthesized in a similar manner.

Some specific structural examples of metal coordination compounds usedin the present invention are shown in Tables 1 to Tables 17 appearinghereinafter, which are however only representative examples and are notexhaustive. Pi to Bf6 for CyN1, CyN2, CyC1 and CyC2 shown in Tables 1 to17 represent partial structures shown below.

Further, aromatic group Ph2 to Bf8 as substituents for CyN1, CyN2, CyC1and CyC2 shown in Tables 1 to 17 represent partial structures shownbelow.

TABLE 1 CyN1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyC1 No M m n CyN1 CyC1 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 1 Ir 3 0 Pi Bf1 H H — — — — H H HH — — — — 2 Ir 3 0 Pi Bf1 CF₃ H — — — — H H H H — — — — 3 Ir 3 0 Pi Bf1CF₃ CF₃ — — — — H H H H — — — — 4 Ir 3 0 Pi Bf1 H CF₃ — — — — H H H H —— — — 5 Ir 3 0 Pi Bf1 H NO₂ — — — — H H H H — — — — 6 Ir 3 0 Pi Bf1 H Cl— — — — H H H H — — — — 7 Ir 3 0 Pi Bf1 H F F — — — — H H H H — — — — 8Ir 3 0 Pi Bf1 H CN — — — — H H H H — — — — 9 Ir 3 0 Pi Bf1 H OCH₃ — — —— H H H H — — — — 10 Ir 3 0 Pi Bf1 H Ph2 H H H H H H H H — — — — 11 Ir 30 Pi Bf1 H Ph2 CF₃ H H H H H H H — — — — 12 Ir 3 0 Pi Bf1 H Ph2 H H F FH H H H — — — — 13 Ir 3 0 Pi Bf1 Ph2 H H H H H H H H H — — — — 14 Ir 3 0Pi Bf1 H Np4 H — — — H H H H — — — — 15 Ir 3 0 Pi Bf1 Tn7 H H H — — H HH H — — — — 16 Ir 3 0 Pi Bf1 H C₄H₉ — — — — H H H H — — — — 17 Ir 3 0 PiBf1 H H — — — — H H OCH₃ H — — — — 18 Ir 3 0 Pi Bf1 H H — — — — H H Cl H— — — — 19 Ir 3 0 Pi Bf1 H H — — — — H H F H — — — — 20 Ir 3 0 Pi Bf1 HH — — — — H H C₈H₁₇ H — — — — 21 Ir 3 0 Pi Bf1 H H — — — — H H NO₂ H — —— — 22 Ir 3 0 Pi Bf1 H H — — — — H H Ph2 H H H H H 23 Ir 3 0 Pi Bf1 H H— — — — H H Ph2 H H Si(C₃H₇)₃ H H 24 Ir 3 0 Pi Bf1 Ph2 H H H H H H H Ph2H H H H H 25 Ir 3 0 Pi Bf1 H H — — — — H H Br H — — — — 26 Ir 3 0 Pi Bf1H H — — — — H H Bf7 H H H H H 27 Ir 3 0 Pi Bf1 H H — — — — H OC₄H₉ H H —— — — 28 Ir 3 0 Pi Bf1 H Ph2 H OCH₂C₅F₁₁ H H H H H H — — — — 29 Ir 3 0Pi Bf1 H H — — — — H Br H H — — — — 30 Ir 3 0 Pi Bf1 H H — — — — HSi(C₈H1₇)₃ H H — — — — 31 Ir 3 0 Pi Bf2 H H — — — — H H H H — — — —

TABLE 2 CyN1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyC1 No M m n CyN1 CyC1 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 32 Ir 3 0 Pi Bf2 CF₃ H — — — — H HH H — — — — 33 Ir 3 0 Pi Bf2 CF₃ CF₃ — — — — H H H H — — — — 34 Ir 3 0Pi Bf2 H CF₃ — — — — H H H H — — — — 35 Ir 3 0 Pi Bf2 Ph2 H H H H H H HH H — — — — 36 Ir 3 0 Pi Bf2 H Np4 H — — — H H H H — — — — 37 Ir 3 0 PiBf2 Tn7 H H H — — H H H H — — — — 38 Ir 3 0 Pi Bf2 H C₄H₉ — — — — H H HH — — — — 39 Ir 3 0 Pi Bf2 H H — — — — H H OCH₃ H — — — — 40 Ir 3 0 PiBf2 H H — — — — H H Ph2 H H Si(C₃H₇)₃ H H 41 Ir 3 0 Pi Bf2 Ph2 H H H H HH H Ph2 H H H H H 42 Ir 3 0 Pi Bf2 H Np3 H H — — H H H H — — — — 43 Ir 30 Pi Bf2 H Np4 H — — — H H H H — — — — 44 Ir 3 0 Pi Bf2 H Pe2 H — — — HH H H — — — — 45 Ir 3 0 Pi Bf2 H Qn2 H H — — H H H H — — — — 46 Ir 3 0Pi Bf2 H An H — — — H H H H — — — — 47 Ir 3 0 Pi Bf2 H Bf7 H H H H H H HH — — — — 48 Ir 3 0 Pi Bf2 Tn5 H H H — — H H H H — — — — 49 Ir 3 0 PiBf2 H Bf8 H H H H H H H H — — — — 50 Ir 3 0 Pi Bf2 H Tn6 H H — — H H H H— — — — 51 Ir 3 0 Pi Bf3 H H — — — — Ph2 H H H H OCH₃ H H 52 Ir 3 0 PiBf3 H CF₃ — — — — Ph2 H H H H C₆H₁₃ H H 53 Ir 3 0 Pi Bf3 H CF₃ — — — —Np3 H H H H H — — 54 Ir 3 0 Pi Bf3 H H — — — — H H H H — — — — 55 Ir 3 0Pi Bf3 CF₃ H — — — — C₂H₅ H H H — — — — 56 Ir 3 0 Pi Bf3 CF₃ CF₃ — — — —C₁₀H₂₁ H H H — — — — 57 Ir 3 0 Pi Bf3 H CF₃ — — — — H H H H — — — — 58Ir 3 0 Pi Bf3 H H — — — — Tn5 H H H H H — — 59 Ir 3 0 Pi Bf3 H H — — — —Np3 H H H H H — — 60 Ir 3 0 Pi Bf3 H H — — — — Np4 H H H H — — — 61 Ir 30 Pi Bf4 H CF₃ — — — — Ph2 H H H H C₅H₁₃ H H

TABLE 3 CyN1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyC1 No M m n CyN1 CyC1 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 62 Ir 3 0 Pi Bf4 H H — — — — C₈H₁₇H H H — — — — 63 Ir 3 0 Pi Bf4 H H — — — — Ph2 H H H H H H H 64 Ir 3 0Pi Bf4 Np4 H H — — — Ph2 H H H H H H H 65 Ir 3 0 Pi Bf4 FL4 H H H H —Ph2 H H H H H H H 66 Ir 3 0 Pi Bf4 CF₃ CF₃ — — — — C₁₅H₃₁ H H H — — — —67 Ir 3 0 Pi Bf4 H H — — — — DBT2 H H H H H H — 68 Ir 3 0 Pi Bf4 H Bf7 HH H H Ph2 H H H H H H H 69 Ir 3 0 Pi Bf4 H Bf8 H H H H Ph2 H H H H H H H70 Ir 3 0 Pi Bf4 H Pi3 H H — — Ph2 H H H H H H H 71 Ir 3 0 Pi Bf5 H CF₃— — — — Ph2 H H H H C₆H₁₃ H H 72 Ir 3 0 Pi Bf5 H H — — — — C₃H₇ H H H —— — — 73 Ir 3 0 Pi Bf5 CF₃ H — — — — C₂₀H₄₁ H H H — — — — 74 Ir 3 0 PiPh1 H Bf7 H H H H H H — — — — — — 75 Ir 3 0 Pi Ph1 H Bf7 H H H H H OCH₃— — — — — — 76 Ir 3 0 Pi Tn1 H Bf7 H H H H H H — — — — — — 77 Ir 3 0 PiNp2 H Bf7 H H H H H H — — — — — — 78 Ir 3 0 Pi Cn1 H Bf7 H H H H H H — —— — — — 79 Ir 3 0 Pi DBT1 H Bf7 H H H H H H — — — — — — 80 Ir 3 0 Pi Ph1H Bf8 H H H H H H — — — — — — 81 Ir 3 0 Pi Ph1 H Bf8 H H H H H H — — — —— — 82 Ir 3 0 Pi Tn2 H Bf8 H H H H H H — — — — — — 83 Ir 3 0 Pi Np2 HBf8 H H F H H H — — — — — — 84 Ir 3 0 Pi Cn1 H Bf8 H H H H H H — — — — —— 85 Ir 3 0 Pi Cz H Bf8 H H H H CH3 H — — — — — — 86 Ir 3 0 Pr Bf1 H H —— — — H H H H — — — — 87 Ir 3 0 Py1 Bf1 H — — — — — H H H H — — — — 88Ir 3 0 Py2 Bf1 — H — — — — H H H H — — — — 89 Ir 3 0 Pr Bf2 H H — — — —H H H H — — — — 90 Ir 3 0 Py1 Bf2 H — — — — — H H H H — — — — 91 Ir 3 0Pi Bf1 H H — — — — —(CH═CH)2— H H — — — — 92 Ir 3 0 Pi Bf1 H H — — — — H—(CH═CH)2— H — — — —

TABLE 4 CyN1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyC1 No M m n CyN1 CyC1 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 93 Ir 3 0 Pi Bf1 H H — — — — H H—(CH═CH)2— — — — — 94 Ir 3 0 Pi Bf1 H CF₃ — — — — —(CH═CH)2— H H — — — —95 Ir 3 0 Pi Bf1 H CF₃ — — — — H —(CH═CH)2— H — — — — 96 Ir 3 0 Pi Bf1 HCF₃ — — — — H H —(CH═CH)2— — — — — 97 Ir 3 0 Pi Bf1 H Np4 H — — ——(CH═CH)2— H H — — — — 98 Ir 3 0 Pi Bf1 H Ph2 H OCH═CHC₇H₁₅ H H—(CH═CH)2— H H — — — — 99 Ir 3 0 Pi Bf1 H Ph2 H OC≡CC₈H₁₇ H H H—(CH═CH)2— H — — — — 100 Ir 3 0 Pi Bf1 Ph2 H H H H H H H —(CH═CH)2— — —— — 101 Ir 3 0 Pi Bf2 H H — — — — H —(CH═CH)2— H — — — — 102 Ir 3 0 PiBf2 H H — — — — H H —(CH═CH)2— — — — — 103 Ir 3 0 Pi Bf2 H H — — — — H—(CH═CH)2— H — — — — 104 Ir 3 0 Pi Bf2 H Np4 H — — — H H —(CH═CH)2— — —— — 105 Ir 3 0 Pi Bf2 H Ph2 H H F F H H —(CH═CH)2— — — — — 106 Ir 3 0 PiBf1 H Np3 H H — — —(CH═CH)2— H H — — — — 107 Ir 3 0 Pi Bf1 H An H — — —H —(CH═CH)2— H — — — — 108 Ir 3 0 Pi Bf1 H Pe2 H — — — H H —(CH═CH)2— —— — — 109 Ir 3 0 Pi Bf1 H Cl — — — — —(CH═CH)2— H H — — — — 110 Ir 3 0Pi Bf1 H Tn8 H H — — H —(CH═CH)2— H — — — — 111 Ir 3 0 Pi Bf1 H Pi3 H H— — H H —(CH═CH)2— — — — — 112 Ir 3 0 Pi Bf1 H Qn2 H H — — —(CH═CH)2— HH — — — — 113 Ir 3 0 Pi Bf1 H Ph2 H OCOC₇H₁₅ H H —(CH═CH)2— H H — — — —114 Ir 3 0 Pi Bf1 H Ph2 H CN H H H —(CH═CH)2— H — — — — 115 Ir 3 0 PiBf2 H Tn5 H H — — H —(CH═CH)2— H — — — — 116 Ir 3 0 Pi Bf2 H Tn6 H H — —H H —(CH═CH)2— — — — — 117 Ir 3 0 Pi Bf2 H Tn7 H H — — H —(CH═CH)2— H —— — — 118 Ir 3 0 Pi Bf2 H Pi2 H H — — H H —(CH═CH)2— — — — — 119 Ir 3 0Pi Bf2 H Ph2 NO₂ H H H H H —(CH═CH)2— — — — — 120 Ir 3 0 Pi Bf2 H DBF3 HH H — H H —(CH═CH)2— — — — — 121 Rh 3 0 Pi Bf1 H H — — — — H H H H — — —— 122 Rh 3 0 Pi Bf1 CF₃ H — — — — H H H H — — — —

TABLE 5 CyN1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyC1 No M m n CyN1 CyC1 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 123 Rh 3 0 Pi Bf1 CF₃ CF₃ — — — —H H H H — — — — 124 Rh 3 0 Pi Bf1 H CF₃ — — — — H H H H — — — — 125 Rh 30 Pi Bf1 H NO₂ — — — — H H H H — — — — 126 Rh 3 0 Pi Bf1 H Cl — — — — HH H H — — — — 127 Rh 3 0 Pi Bf1 H F F — — — — H H H H — — — — 128 Rh 3 0Pi Bf1 H CN — — — — H H H H — — — — 129 Rh 3 0 Pi Bf1 H OCH₃ — — — — H HH H — — — — 130 Rh 3 0 Pi Bf1 H Ph2 H H H H H H H H — — — — 131 Rh 3 0Pi Bf2 H H — — — — H H H H — — — — 132 Rh 3 0 Pi Bf2 CF₃ H — — — — H H HH — — — — 133 Rh 3 0 Pi Bf2 CF₃ CF₃ — — — — H H H H — — — — 134 Rh 3 0Pi Bf2 H CF₃ — — — — H H H H — — — — 135 Rh 3 0 Pi Bf2 Ph2 H H H H H H HH H — — — — 136 Rh 3 0 Pi Bf2 H Np4 H — — — H H H H — — — — 137 Rh 3 0Pi Bf2 Tn7 H H H — — H H H H — — — — 138 Rh 3 0 Pi Bf2 H C₄H₉ — — — — HH H H — — — — 139 Rh 3 0 Pi Bf2 H H — — — — H H OCH₃ H — — — — 140 Rh 30 Pi Bf2 H H — — — — H H Ph2 H H Si(C₃H₇)₃ H H 141 Pt 2 0 Pi Bf1 H H — —— — —(CH═CH)2— H H — — — — 142 Pt 2 0 Pi Bf1 H H — — — — H —(CH═CH)2— H— — — — 143 Pt 2 0 Pi Bf1 H H — — — — H H —(CH═CH)2— — — — — 144 Pt 2 0Pi Bf2 H Tn5 H H — — H —(CH═CH)2— H — — — — 145 Pt 2 0 Pi Bf2 H Tn6 H H— — H H —(CH═CH)2— — — — — 146 Pt 2 0 Pi Bf2 H Tn7 H H — — H —(CH═CH)2—H — — — — 147 Pt 2 0 Pi Bf2 H Pi2 H H — — H H —(CH═CH)2— — — — — 148 Pd2 0 Pi Bf4 H Pi3 H H — — Ph2 H H H H H H H 149 Pd 2 0 Pi Bf5 H CF₃ — — —— Ph2 H H H H C₆H₁₃ H H 150 Pd 2 0 Pi Bf1 H H — — — — H H Ph2 H HSi(C₃H₇)₃ H H

TABLE 6 CyN1 R5 R6 R7 R8 CyC1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyN2 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 CyN1 CyC1 CyN2-R1 CyN2-R2 CyC2 NoM m n CyN2 CyC2 CyC2-R3 CyC2-R4 CyC2-R′3 CyC2-R′4 R5 R6 R7 R8 151 Ir 2 1Pi Bf1 H H — — — — H H H H — — — — Pi Ph1 H H — — — — H H — — — — — —152 Ir 2 1 Pi Bf1 CF₃ H — — — — H H H H — — — — Pi Ph1 H H — — — — H H —— — — — — 153 Ir 2 1 Pi Bf1 CF₃ CF₃ — — — — H H H H — — — — Pi Ph1 H H —— — — H H — — — — — — 154 Ir 2 1 Pi Bf1 H CF₃ — — — — H H H H — — — — PiPh1 H H — — — — H H — — — — — — 155 Ir 2 1 Pi Bf1 H CF₃ — — — — H H H H— — — — Pi Np2 H H — — — — H H — — — — — — 156 Ir 2 1 Pi Bf1 H Ph2 H H HH H H H H — — — — Pi Ph1 H H — — — — H H — — — — — — 157 Ir 2 1 Pi Bf2 HH — — — — H H H H — — — — Pi Ph1 H H — — — — H H — — — — — — 158 Ir 2 1Pi Bf2 CF₃ H — — — — H H H H — — — — Pi Ph1 H H — — — — H H — — — — — —159 Ir 2 1 Pi Bf2 CF₃ CF₃ — — — — H H H H — — — — Pi Ph1 H H — — — — H H— — — — — — 160 Ir 2 1 Pi Bf2 H CF₃ — — — — H H H H — — — — Pi Ph1 H H —— — — H H — — — — — — 161 Ir 2 1 Pi Bf2 H CF₃ — — — — H H H H — — — — PiPh1 CF₃ H — — — — H H — — — — — —

TABLE 7 CyN1 R5 R6 R7 R8 CyC1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyN2 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 CyN1 CyC1 CyN2-R1 CyN2-R2 CyC2 NoM m n CyN2 CyC2 CyC2-R3 CyC2-R4 CyC2-R′3 CyC2-R′4 R5 R6 R7 R8 162 Ir 2 1Pi Bf2 H Ph2 H H H H H H H H — — — — Pi Ph1 H H — — — — H H — — — — — —163 Ir 2 1 Pi Bf2 Ph2 H H H H H H H H H — — — — Pi Ph1 H H — — — — H H —— — — — — 164 Ir 2 1 Pi Bf2 Tn7 H H H — — H H H H — — — — Pi Ph1 H H — —— — H H — — — — — — 165 Ir 2 1 Pi Bf2 H C₄H₉ — — — — H H H H — — — — PiPh1 H H — — — — H H — — — — — — 166 Ir 2 1 Pi Bf2 H H — — — — H H Ph2 HH Si(C₃H₇)₃ H H Pi Ph1 H H — — — — H H — — — — — — 167 Ir 2 1 Pi Bf2 Ph2H H H H H H H Ph2 H H H H H Pi Ph1 H H — — — — H H — — — — — — 168 Ir 21 Pi Bf2 H Qn2 H H — — H H H H — — — — Pi Ph1 H H — — — — H H — — — — —— 169 Ir 2 1 Pi Bf2 H Bf7 H H H H H H H H — — — — Pi Ph1 H H — — — — H H— — — — — — 170 Ir 2 1 Pi Bf2 H Bf8 H H H H H H H H — — — — Pi Ph1 H H —— — — H H — — — — — — 171 Ir 2 1 Pi Bf3 H H — — — — Ph2 H H H H OCH₃ H HPi Ph1 H H — — — — H H — — — — — — 172 Ir 2 1 Pi Bf3 H CF₃ — — — — Np3 HH H H H — — Pr Ph1 H H — — — — H H — — — — — —

TABLE 8 CyN1 R5 R6 R7 R8 CyC1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyN2 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 CyN1 CyC1 CyN2-R1 CyN2-R2 CyC2 NoM m n CyN2 CyC2 CyC2-R3 CyC2-R4 CyC2-R′3 CyC2-R′4 R5 R6 R7 R8 173 Ir 2 1Pi Bf4 H CF₃ — — — — Ph2 H H H H C₆H₁₃ H H Py1 Ph1 H — — — — — H H — — —— — — 174 Ir 2 1 Pi Bf4 H Bf7 H H H H Ph2 H H H H H H H Py2 Ph1 — H — —— — H H — — — — — — 175 Ir 2 1 Pi Ph1 H Bf7 H H H H H OCH₃ — — — — — —Pi Ph1 H H — — — — H H — — — — — — 176 Ir 2 1 Pi Np2 H Bf7 H H H H H H —— — — — — Pi Ph1 H H — — — — H H — — — — — — 177 Ir 2 1 Pi Tn2 H Bf8 H HH H H H — — — — — — Pi Ph1 H H — — — — H H — — — — — — 178 Ir 2 1 Pi Cn1H Bf8 H H H H H — — — — — — — Pi Ph1 H Np3 H H — — H H — — — — — — 179Ir 2 1 Pi Bf1 H H — — — — —(CH═CH)2— H H — — — — Pi Np2 H H — — — — H H— — — — — — 180 Ir 2 1 Pi Bf1 H H — — — — H —(CH═CH)2— H — — — — Pi Ph1H CF₃ — — — — H H — — — — — — 181 Ir 2 1 Pi Bf1 H H — — — — H H—(CH═CH)2— — — — — Pi Bf2 H CF₃ — — — — H H H H — — — — 182 Ir 2 1 PiBf1 H CF₃ — — — — —(CH═CH)2— H H — — — — Pi Ph1 H CF₃ — — — — H H — — —— — — 183 Ir 2 1 Pi Bf1 H CF₃ — — — — H —(CH═CH)2— H — — — — Pi Ph1 H H— — — — H H — — — — — —

TABLE 9 CyN1 R5 R6 R7 R8 CyC1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyN2 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 CyN1 CyC1 CyN2-R1 CyN2-R2 CyC2 NoM m n CyN2 CyC2 CyC2-R3 CyC2-R4 CyC2-R′3 CyC2-R′4 R5 R6 R7 R8 184 Ir 2 1Pi Bf1 H CF₃ — — — — H H —(CH═CH)2— — — — — Pi Bf2 H CF₃ — — — — H H H H— — — — 185 Ir 2 1 Pi Bf1 H Np4 H — — — —(CH═CH)2— H H — — — — Pi Ph1 HH — — — — H H — — — — — — 186 Ir 2 1 Pi Bf1 H Ph2 H OCH═CHC₇H₁₅ H H—(CH═CH)2— H H — — — — Pi Ph1 H CF₃ — — — — H H — — — — — — 187 Ir 2 1Pi Bf1 H Ph2 H OC≡CC₈H₁₇ H H H —(CH═CH)2— H — — — — Pi Np2 H H — — — — HH — — — — — — 188 Ir 2 1 Pi Bf1 Ph2 H H H H H H H —(CH═CH)2— — — — — PiBf2 H CF₃ — — — — H H H H — — — — 189 Ir 2 1 Pi Bf2 H H — — — — H—(CH═CH)2— H — — — — Pi Ph1 H H — — — — H H — — — — — — 190 Ir 2 1 PiBf2 H H — — — — H H —(CH═CH)2— — — — — Pi Ph1 H H — — — — H H — — — — —— 191 Ir 2 1 Pi Bf2 H H — — — — H —(CH═CH)2— H — — — — Pi Ph1 H H — — —— H H — — — — — — 192 Ir 2 1 Pi Bf2 H Np4 H — — — H H —(CH═CH)2— — — — —Pi Ph1 H CF₃ — — — — H H — — — — — — 193 Ir 2 1 Pi Bf2 H Ph2 H H F F H H—(CH═CH)2— — — — — Pi Ph1 H H — — — — H H — — — — — — 194 Ir 2 1 Pi Bf1H Np3 H H — — —(CH═CH)2— H H — — — — Pi Ph1 H H — — — — H H — — — — — —

TABLE 10 CyN1 R5 R6 R7 R8 CyC1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyN2 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 CyN1 CyC1 CyN2-R1 CyN2-R2 CyC2 NoM m n CyN2 CyC2 CyC2-R3 CyC2-R4 CyC2-R′3 CyC2-R′4 R5 R6 R7 R8 195 Ir 2 1Pi Bf1 H An H — — — H —(CH═CH)2— H — — — — Pi Bf2 H CF₃ — — — — H H H H— — — — 196 Ir 2 1 Pi Bf1 H Pe2 H — — — H H —(CH═CH)2— — — — — Pi Ph1 HCF₃ — — — — H H — — — — — — 197 Ir 2 1 Pi Bf1 H Cl — — — — —(CH═CH)2— HH — — — — Pi Ph1 H H — — — — H H — — — — — — 198 Ir 2 1 Pi Bf1 H Tn8 H H— — H —(CH═CH)2— H — — — — Pi Ph1 H H — — — — H H — — — — — — 199 Ir 2 1Pi Bf1 H Pi3 H H — — H H —(CH═CH)2— — — — — Pi DBT1 H H — — — — H H — —— — — — 200 Ir 2 1 Pi Bf1 H Qn2 H H — — —(CH═CH)2— H H — — — — Pi Ph1 HH — — — — H H — — — — — — 201 Ir 2 1 Pi Bf1 H Ph2 H OCOC₇H₁₅ H H—(CH═CH)2— H H — — — — Pi Bf2 H CF₃ — — — — H H H H — — — — 202 Ir 2 1Pi Bf1 H Ph2 H CN H H H —(CH═CH)2— H — — — — Pi Ph1 H CF₃ — — — — H H —— — — — — 203 Rh 2 1 Pi Bf2 H Tn6 H H — — H H —(CH═CH)2— — — — — Pi Ph1H H — — — — H H — — — — — — 204 Rh 2 1 Pi Bf2 H Ph2 NO₂ H H H H H—(CH═CH)2— — — — — Pi Ph1 H H — — — — H H — — — — — — 205 Rh 2 1 Pi Bf2H DBF3 H H H — H H —(CH═CH)2— — — — — Pi Bf2 H CF₃ — — — — H H H H — — ——

TABLE 11 CyN1 R5 R6 R7 R8 CyC1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyN2 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 CyN1 CyC1 CyN2-R1 CyN2-R2 CyC2 NoM m n CyN2 CyC2 CyC2-R3 CyC2-R4 CyC2-R′3 CyC2-R′4 R5 R6 R7 R8 206 Rh 2 1Pi Bf2 H H — — — — H H Ph2 H H Si(C₃H₇)₃ H H Pi Ph1 H H — — — — H H — —— — — — 207 Rh 2 1 Pi Bf2 Ph2 H H H H H H H Ph2 H H H H H Pi Ph1 H H — —— — H H — — — — — — 208 Rh 2 1 Pi Bf2 H Pe2 H — — — H H H H — — — — PiPh1 H GF₃ — — — — H H — — — — — — 209 Rh 2 1 Pi Bf2 H An H — — — H H H H— — — — Pi Ph1 H H — — — — H H — — — — — — 210 Rh 2 1 Pi Bf2 H Bf8 H H HH H H H H — — — — Pi Ph1 H H — — — — H H — — — — — — 211 Ir 1 2 Pi Bf1 HH — — — — H H H H — — — — Pi Ph1 H H — — — — H H — — — — — — 212 Ir 1 2Pi Bf1 CF₃ H — — — — H H H H — — — — Pi Ph1 H H — — — — H H — — — — — —213 Ir 1 2 Pi Bf1 CF₃ CF₃ — — — — H H H H — — — — Pi Ph1 H H — — — — H H— — — — — — 214 Ir 1 2 Pi Bf1 H CF₃ — — — — H H H H — — — — Pi Ph1 H H —— — — H H — — — — — — 215 Ir 1 2 Pi Bf1 H CF₃ — — — — H H H H — — — — PiNp2 H H — — — — H H — — — — — — 216 Ir 1 2 Pi Bf2 H H — — — — H H H H —— — — Pi Ph1 H H — — — — H H — — — — — —

TABLE 12 CyN1 R5 R6 R7 R8 CyC1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyN2 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 CyN1 CyC1 CyN2-R1 CyN2-R2 CyC2 NoM m n CyN2 CyC2 CyC2-R3 CyC2-R4 CyC2-R′3 CyC2-R′4 R5 R6 R7 R8 217 Ir 1 2Pi Bf2 CF₃ H — — — — H H H H — — — — Pi Ph1 H H — — — — H H — — — — — —218 Ir 1 2 Pi Bf2 CF₃ CF₃ — — — — H H H H — — — — Pi Ph1 H H — — — — H H— — — — — — 219 Ir 1 2 Pi Bf2 H CF₃ — — — — H H H H — — — — Pi Ph1 H H —— — — H H — — — — — — 220 Ir 1 2 Pi Bf2 H CF₃ — — — — H H H H — — — — PiPh1 CF₃ H — — — — H H — — — — — — 221 Ir 1 2 Pi Bf2 H Ph2 H H H H H H HH — — — — Pi Ph1 H H — — — — H H — — — — — — 222 Ir 1 2 Pi Bf1 H H — — —— —(CH═CH)2— H H — — — — Pi Np2 H H — — — — H H — — — — — — 223 Ir 1 2Pi Bf1 H H — — — — H —(CH═CH)2— H — — — — Pi Ph1 H CF₃ — — — — H H — — —— — — 224 Ir 1 2 Pi Bf1 H CF₃ — — — — H H —(CH═CH)2— — — — — Pi Bf2 HCF₃ — — — — H H H H — — — — 225 Ir 1 2 Pi Bf1 H Np4 H — — — —(CH═CH)2— HH — — — — Pi Ph1 H H — — — — H H — — — — — — 226 Ir 1 2 Pi Bf1 H Ph2 HOCH═CHC₇H₁₅ H H —(CH═CH)2— H H — — — — Pi Ph1 H CF₃ — — — — H H — — — —— — 227 Ir 1 2 Pi Bf1 H Ph2 H OC≡CC₈H₁₇ H H H —(CH═CH)2— H — — — — PiNp2 H H — — — — H H — — — — — —

TABLE 13 CyN1 R5 R6 R7 R8 CyC1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyN2 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 CyN1 CyC1 CyN2-R1 CyN2-R2 CyC2 NoM m n CyN2 CyC2 CyC2-R3 CyC2-R4 CyC2-R′3 CyC2-R′4 R5 R6 R7 R8 228 Ir 1 2Pi Bf1 H Qn2 H H — — —(CH═CH)2— H H — — — — Pi Ph1 H H — — — — H H — — —— — — 229 Ir 1 2 Pi Bf1 H Ph2 H OCOC₇H₁₅ H H —(CH═CH)2— H H — — — — PiBf2 H CF₃ — — — — H H H H — — — — 230 Ir 1 2 Pi Bf1 H Ph2 H CN H H H—(CH═CH)2— H — — — — Pi Ph1 H CF₃ — — — — H H — — — — — — 231 Ir 1 2 PiBf2 H Tn6 H H — — H H —(CH═CH)2— — — — — Pi Ph1 H H — — — — H H — — — —— — 232 Ir 1 2 Pi Bf2 H Ph2 NO₂ H H H H H —(CH═CH)2— — — — — Pi Ph1 H H— — — — H H — — — — — — 233 Ir 1 2 Pi Bf2 H DBF3 H H H — H H —(CH═CH)2—— — — — Pi Bf2 H CF₃ — — — — H H H H — — — — 234 Ir 1 2 Pi Bf2 Ph2 H H HH H H H Ph2 H H H H H Pi Ph1 H H — — — — H H — — — — — —

TABLE 14 CyN1 R5 R6 R7 R8 CyC1 R5 R6 R7 R8 CyN1-R1 CyN1-R2 CyN2 CyC1-R3CyC1-R4 CyC1-R′3 CyC1-R′4 R5 R6 R7 R8 CyN1 CyC1 CyN2-R1 CyN2-R2 CyC2 NoM m n CyN2 CyC2 CyC2-R3 CyC2-R4 CyC2-R′3 CyC2-R′4 R5 R6 R7 R8 235 Rh 1 2Pi Bf2 H Pe2 H — — — H H H H — — — — Pi Ph1 H CF₃ — — — — H H — — — — —— 236 Rh 1 2 Pi Bf2 H An H — — — H H H H — — — — Pi Ph1 H H — — — — H H— — — — — — 237 Rh 1 2 Pi Bf2 H Bf8 H H H H H H H H — — — — Pi Ph1 H H —— — — H H — — — — — — 238 Rh 1 2 Pi Bf1 Ph2 H H H H H H H —(CH═CH)2— — —— — Pi Bf2 H CF₃ — — — — H H H H — — — — 239 Pt 1 1 Pi Bf2 H H — — — — H—(CH═CH)2— H — — — — Pi Ph1 H H — — — — H H — — — — — — 240 Pd 1 1 PiBf2 H H — — — — H H —(CH═CH)2— — — — — Pi Ph1 H H — — — — H H — — — — ——

TABLE 15 CyN1 R5 R6 R7 R8 CyC1 R5 R6 R7 R8 CyN1-R1 E CyN1 CyC1 CyC1-R3CyC1-R4 R5 R6 R7 R8 E R″ R″′ CyN1-R2 G No M m n G R″ R″′ CyC1-R′3CyC1-R′4 R5 R6 R7 R8 241 Ir 2 1 Pi Bf1 H H — — — — H H H H — — — — CH₃ —— — — — — CH₃ — — — — — — 242 Ir 2 1 Pi Bf1 CF₃ H — — — — H H H H — — —— CF₃ — — — — — — CF₃ — — — — — — 243 Ir 2 1 Pi Bf1 CF₃ CF₃ — — — — H HH H — — — — CH₃ — — — — — — CH₃ — — — — — — 244 Ir 2 1 Pi Bf1 H CF₃ — —— — H H H H — — — — Ph2 — — H H H H Ph2 — — H H H H 245 Ir 2 1 Pi Bf1 HPh2 H H H H H H H H — — — — Ph2 — — H C₃H₇ H H Ph2 — — H C₃H₇ H H 246 Ir2 1 Pi Bf2 H H — — — — H H H H — — — — CH₃ — — — — — — FL5 CH₃ CH₃ H H H— 247 Ir 2 1 Pi Bf2 CF₃ H — — — — H H H H — — — — Tn5 — — H H — — Tn5 —— H H — — 248 Ir 2 1 Pi Bf2 CF₃ CF₃ — — — — H H H H — — — — Tn6 — — H H— — Tn6 — — H H — — 249 Ir 2 1 Pi Bf2 H CF₃ — — — — H H H H — — — — CH₃— — — — — — CH₃ — — — — — — 250 Ir 2 1 Pi Bf2 H Ph2 H H H H H H H H — —— — CF₃ — — — — — — CF₃ — — — — — — 251 Ir 2 1 Pi Bf2 Ph2 H H H H H H HH H — — — — Np3 — — CH₃O H — — Np3 — — CH₃O H — —

TABLE 16 CyN1 R5 R6 R7 R8 CyC1 R5 R6 R7 R8 CyN1-R1 E CyN1 CyC1 CyC1-R3CyC1-R4 R5 R6 R7 R8 E R″ R″′ CyN1-R2 G No M m n G R″ R″′ CyC1-R′3CyC1-R′4 R5 R6 R7 R8 252 Ir 2 1 Pi Bf2 Tn7 H H H — — H H H H — — — — Np4— — F — — — Np4 — — F — — — 253 Ir 2 1 Pi Bf2 H C₄H₉ — — — — H H H H — —— — Tn7 — — CH₃ H — — Tn7 — — CH₃ H — — 254 Ir 2 1 Pi Bf2 H H — — — — HH Ph2 H H Si(C₃H₇)₃ H H Tn8 — — H H — — Tn8 — — H H — — 255 Ir 2 1 PiBf2 Ph2 H H H H H H H Ph2 H H H H H Pe2 — — H — — — Pe2 — — H — — — 256Ir 2 1 Pi Bf2 H Qn2 H H — — H H H H — — — — Pi2 — — H H — — Pi2 — — H H— — 257 Ir 2 1 Pi Bf2 H Bf7 H H H H H H H H — — — — Pi3 — — CH₃ CH₃ H HPi3 — — CH₃ CH₃ H H 258 Ir 2 1 Pi Bf2 H Bf8 H H H H H H H H — — — — FL4— — H H H — FL4 — — H H H — 259 Ir 2 1 Pi Bf3 H H — — — — Ph2 H H H HOCH₃ H H FL5 C2H5 C2H5 H H H — FL5 (CH2)5Ph3 (CH2)5Ph3 H H H — 260 Ir 21 Pi Bf4 H CF₃ — — — — Ph2 H H H H C₆H₁₃ H H DBF2 — — H H H — DBF2 — — HH H — 261 Ir 2 1 Pi Ph1 H Bf7 H H H H H OCH₃ — — — — — — DBT3 — — H H H— DBT3 — — H H H — 262 Rh 2 1 Pi Bf1 H H — — — — —(CH═CH)2— H H — — — —CH₃ — — — — — — CH₃ — — — — — —

TABLE 17 CyN1 R5 R6 R7 R8 CyC1 R5 R6 R7 R8 CyN1-R1 E CyN1 CyC1 CyC1-R3CyC1-R4 R5 R6 R7 R8 E R″ R″′ CyN1-R2 G No M m n G R″ R″′ CyC1-R′3CyC1-R′4 R5 R6 R7 R8 263 Rh 2 1 Pi Bf1 H H — — — — H —(CH═CH)2— H — — —— CF₃ — — — — — — CF₃ — — — — — — 264 Rh 2 1 Pi Bf1 H H — — — — H H—(CH═CH)2— — — — — Qn2 — — H H — — Qn2 — — H H — — 265 Rh 2 1 Pi Bf2 HCF₃ — — — — H H H H — — — — Np3 — — H H — — Np3 — — H H — — 266 Pt 1 1Pi Bf1 H CF₃ — — — — H H —(CH═CH)2— — — — — CH₃ — — — — — — CH₃ — — — —— — 267 Pt 1 1 Pi Bf1 H Np4 H — — — —(CH═CH)2— H H — — — — CF₃ — — — — —— CF₃ — — — — — — 268 Pd 1 1 Pi Bf1 H Ph2 H OCH═CHC₇H₁₅ H H —(CH═CH)2— HH — — — — CH₃ — — — — — — CH₃ — — — — — — 269 Pd 1 1 Pi Bf2 H CF₃ — — —— H H H H — — — — CF₃ — — — — — — CF₃ — — — — — — 270 Ir 1 2 Pi Bf1 HPh2 H OC≡CC₈H₁₇ H H H —(CH═CH)2— H — — — — CH₃ — — — — — — CH₃ — — — — ——

In the case where the metal coordination compound of the formula (1) isused as a luminescent material, the metal coordination compound usedsingly (as a single luminescent material) or in combination with anotherluminescent material (host compound).

In the latter case, the resultant luminescence material (composition ormixture) may preferably contain the metal coordination compound of theformula (1) in an amount of at most 50 wt. %, more preferably 0.1-20 wt.%. Above 50 wt. %, a resultant luminescence strength is undesirably belowered due to quenching with an increasing concentration in some cases.

Hereinbelow, the present invention will be described more specificallybased on Examples.

EXAMPLE 1 Synthesis of Example Compound No. 34

In a 100-ml-three-necked flask, 2.80 g (15.4 mM) of2-chloro-5-trifluoromethylpyridine, 2.50 g (15.4 mM) of2-benzofuranylboronic acid, 14 ml of toluene, 7 ml of ethanol and 14 mlof 2M-sodium carbonate aqueous solution were placed and stirred at roomtemperature under nitrogen stream, and 0.55 g (0.48 mM) oftetrakis(triphenylphosphine)palladium (0) was added thereto. Thereafter,reflux under stirring for 4 hours was performed under nitrogen stream.After the reaction, the reaction mixture was cooled on an ice bath andstirred at room temperature after addition of ethyl acetate andsaturated saline water. The organic layer was washed with water anddried with anhydrous magnesium sulfate, and the solvent was removedunder reduced pressure to obtain a residue. The residue was purified byalumina column chromatography (eluent: toluene) and recrystallized frommethanol to obtain 0.72 g of2-(5-trifluoromethylpyridine-2-yl)benzofuran (Yield: 17.7%).

In a 100 ml-four-necked flask, 25 ml of glycerol was placed and heatedat 130-140° C. under stirring and bubbling with nitrogen for 2 hours.Then, the glycerol was cooled by standing down to 100° C., and 0.70 g(2.66 mM) of 2-(5-trifluoromethylpyridine-2-yl)benzofuran and 0.23 g(0.47 mM) of iridium (III) acetylacetonate were added, followed by 7hours and 10 minutes of heating at 192-230° C. under stirring andnitrogen stream. The reaction product was cooled to room temperature andinjected into 150 ml of 1N-hydrochloric acid to form a precipitate,which was filtered out, washed with water, and dissolved in acetone toremove the insoluble content. The acetone was distilled off underreduced pressure to obtain a residue. The residue was washed withmethanol and purified by silica gel column chromatography with tolueneas the eluent to obtain 0.11 g (yield=23.4%) of red powderytris[2-(benzofuran-2-yl)-5-trifluoromethyl-pyridine-C³,N]iridium (III).

A toluene solution of the compound exhibited a photoluminescencespectrum showing λmax (maximum emission wavelength)=622 nm and a quantumyield of 0.12.

EXAMPLES 2-10

Each of luminescence devices having a layer structure shown in FIG. 1Bwere prepared in the following manner.

On a 1.1 mm-thick glass substrate (transparent substrate 15), a 100nm-thick film (transparent electrode 14) of ITO (indium tin oxide) wasformed by sputtering, followed by patterning to form a stripe electrodeincluding 100 lines each having a width of 100 nm and a spacing with anadjacent line of 10 nm (i.e., electrode pitch of 110 nm).

On the ITO-formed substrate, three organic layers and two metalelectrode layers shown below were successively formed by vacuum (vapor)deposition using resistance heating in a vacuum chamber (10⁻⁴ Pa).

Organic layer 1 (hole transport layer 13) (40 nm): α-NPD

Organic layer 2 (luminescence layer 12) (30 nm): co-deposited film ofCBP:metal complex (metal coordination compound shown in Table 18) (95:5by weight)

Organic layer 3 (electron transport layer 16) (30 nm): Alq3

Metal electrode layer 1 (metal electrode 11) (15 nm): Al—Li alloy(Li=1.8 wt. %)

Metal electrode layer 2 (metal electrode 11) (100 nm): Al

The above-deposited metal electrode layers 1 and 2 (Al—Li layer and Allayer) had a stripe electrode pattern including 100 lines each having awidth of 100 nm and a spacing of 10 nm (electrode pitch=110 nm) andarranged so that the stripe electrode pattern intersected with that ofthe ITO electrode at right angles to form a matrix of pixels each havingan effective electrode area of 3 mm² comprising 20 ITO lines-bundledtogether at a lead-out portion and 15 Al (Al—Li) lines bundled togetherat a lead-out portion.

Each of the thus-prepared luminescence devices was taken out of thevacuum-chamber and was subjected to a continuous energization (currentpassage) test in an atmosphere of dry nitrogen gas stream so as toremove device deterioration factors, such as oxygen and moisture (watercontent).

The continuous energization test was performed by continuously applyinga voltage at a constant current density of 70 mA/cm² to the luminescencedevice having the ITO (transparent) electrode (as an anode) and the Al(metal) electrode (as a cathode), followed by measurement of emissionluminance (brightness) with time so as to determine a time (luminancehalf-life) required for decreasing an initial luminance (80-250 cd/m²)to ½ thereof.

The results are shown in Table 18 appearing hereinafter.

COMPARATIVE EXAMPLE 1

A comparative luminescence device was prepared and evaluated in the samemanner as in Examples 2-10 except that the Ir complexes (metalcoordination compounds shown in Table 185) was changed toIr-phenylpyrimidine complex (Ir(ppy)₃) shown below.

The results are also also shown in Table 18 below. TABLE 18 Ex. No.Compound No. Luminance half-life (Hr) Ex. 2 4 800 Ex. 3 10 900 Ex. 4 31750 Ex. 5 34 900 Ex. 6 92 800 Ex. 7 115 650 Ex. 8 135 750 Ex. 9 156 850Ex. 10 238 600 Comp. Ex. 1 Ir(ppy)₃ 350

As is apparent from Table 18, compared with the conventionalluminescence device using Ir(ppy)₃, the luminescence devices using themetal coordination compounds of formula (1) according to the presentinvention provide longer luminance half-lives, thus resulting in an ELdevice having a high durability (luminance stability) based on a goodstability of the metal coordination compound of formula (1) of thepresent invention.

EXAMPLE 11

A color organic EL display apparatus shown in FIG. 2 was prepared in thefollowing manner.

An active matrix substrate had a planar structure basically similar to astructure described in U.S. Pat. No. 6,114,715.

Specifically, on a 1.1 mm-thick glass substrate, top gate-type TFTs ofpolycrystalline silicon were formed in an ordinary manner and thereon, aflattening film was formed with contact holes for electrical connectionwith a pixel electrode (anode) at respective source regions, thuspreparing an active matrix substrate with a TFT circuit.

On the active matrix substrate, a 700 nm-thick pixel electrode (anode)of ITO having a large work function was formed in a prescribed pattern.On the ITO electrode, prescribed organic layers and a 100 nm-thick Alelectrode (cathode) were successively formed by vacuum deposition with ahard mask, followed by patterning to form a matrix of color pixels(128×128 pixels).

The respective organic layers corresponding to three color pixels (red(R) green (G) and blue (B)) were consisting of the following layers.

-   <R pixel region>    -   α-NPD (40 nm)/CBP: Ex. Comp. No. 34 (93:7 by weight) (30 nm)/BCP        (20 nm)/Alq 3 (40 nm)-   <G pixel region>    -   α-NPD (50 nm)/Alq 3 (50 nm)-   <B pixel region>    -   α-NPD (50 nm)/BCP (20 nm)/Alq 3 (50 nm)

When the thus-prepared color organic EL display apparatus was driven,desired color image data can be displayed stably with good imagequalities.

EXAMPLE 12 Synthesis of Ex. Comp. No. 31

It is easy to synthesize the following compound in the same manner as inExample 1 except for using 2-bromopyridine (made by Tokyo Kasei KogyoK.K.) instead of 2-chloro-5-trifluoromethylpyridine in Example 1.

Tris[2-(benzofuran-2-yl)pyridine-C³,N]iridium (III).

EXAMPLE 13 Synthesis of Ex. Comp. No. 32

It is easy to synthesize the following compound in the same manner as inExample 1 except for using 2-chloro-4-trifluoromethylpyridine (made byFlorochem USA) instead of 2-chloro-5-trifluoromethylpyridine in Example1.

Tris[2-(benzofuran-2-yl)-4-trifluoromethyl-pyridine-C³,N]iridium (III).

EXAMPLE 14 Synthesis of Ex. Comp. No. 33

It is easy to synthesize the following compound in the same manner as inExample 1 except for using 2-chloro-4,5-bis(trifluoro-methyl)pyridine(made by Oakwood Products Inc.) instead of2-chloro-5-trifluoromethylpyridine in Example 1.

Tris[2-(benzofuran-2-yl)-4,5-bis(trifluoro-methyl)pyridine-C³, N]iridium(III).

EXAMPLE 15 Synthesis of Ex. Comp. No. 35

It is easy to synthesize the following compound in the same manner as inExample 16 except for using 4-phenyl-2-bromopyridine (made by GeneralIntermediates of Canada) instead of 2-chloro-5-trifluoromethylpyridinein Example 1.

Tris[2-(benzofuran-2-yl)-4-pyridine-C³,N]-iridium (III).

EXAMPLE 16 Synthesis of Ex. Comp. No. 36

It is easy to synthesis the following compound in the same manner as inExample 1 except that 2-(benzofuran-2-yl)-5-bromopyridine wassynthesized from 2,5-dibromopyridine (made by Tokyo Kasei Kogyo K.K.)and 2-benzofuranboronic acid (made by Aldrich Co.) and is reacted with1-naphthylboronic acid (made by Tokyo Kasei Kogyo) to obtain2-(benzofuran-2-yl)-5-(naphthalene-1-yl)pyridine, which is used insteadof 2-(5-trifluoromethylpyridine-2-yl)benzofuran.

Tris[2-(benzofuran-2-yl)-5-(naphthalene-1-yl)pyridine-C³,N]iridium(III).

EXAMPLE 17 Synthesis of Ex. Comp. No. 42

It is easy to synthesize the following compound in the same manner as inExample 16 except for using 2-naphthylboronic acid (made by Tokyo KaseiKogyo K.K.) instead of 1-naphthylboronic acid in Example 16.

Tris[2-(benzofuran-2-yl)-5-(naphthalene-2-yl)pyridine-C³,N]iridium(III).

EXAMPLE 18 Synthesis of Ex. Comp. No. 47

It is easy to synthesize the following compound in the same manner as inExample 1 except for reacting 2 equivalent amount of 2-benzofuranboronic acid (made by Aldrich Co.) with 2,5-dibromopyridine (made byTokyo Kasei Kogyo K.K.) to synthesis 2,5-bis(benzofuran-2-yl)pyridine,which is used instead of 2-(5-trifluoromethylpyridine-2-yl)benzofuran,in Example 1.

Tris[2,5-bis(benzofuran-2-yl)pyridine-C³,N]iridium (III).

EXAMPLE 19 Synthesis of Ex. Comp. No. 50

It is easy to synthesis the following compound in the same manner as inExample 1 except that 2-(benzofuran-2-yl)-5-bromopyridine wassynthesized from 2,5-dibromopyridine (made by Tokyo Kasei Kogyo K.K.)and 2-benzofuranboronic acid (made by Aldrich Co.) and is reacted with3-thiopheneboronic acid (made by Aldrich Co.) to obtain2-(benzofuran-2-yl)-5-(thiophene-3-yl)pyridine, which is used instead of2-(5-trifluoromethylpyridine-2-yl)benzofuran.

Tris[2-(benzofuran-2-yl)-5-(thiophene-3-yl)pyridine-C³, N]iridium (III).

EXAMPLE 20

An organic EL device shown in FIG. 1C was prepared in the followingmanner.

On a 100 nm-thick patterned ITO electrode (anode) formed on a 1.1mm-thick no-alkali glass substrate, a 40 nm-thick charge transport layerof α-NPD was formed by vacuum deposition (10⁻⁴ Pa) at a deposition rateof 0.1 nm/sec. On the charge transport layer, a 40 nm-thick luminescencelayer (co-deposited film) of CBP: iridium complex of Ex. Comp. No. 34prepared in Example 1 (97:3 by weight) was formed by co-vacuumdeposition at deposition rates of 0.1 nm/sec (for CBP) and 0.08 nm/sec(for the iridium complex) by controlling heating conditions ofdeposition vessel. On the luminescence layer, a 10 nm-thick excitondiffusion prevention layer of BCP (Bathocuproine) was formed by vacuumdeposition at a deposition rate of 0.1 nm/sec, and or the excitondiffusion prevention layer, a 20 nm-thick electron transport layer ofAlq 3 was formed by vacuum deposition at a deposition rate of 0.1nm/sec. Thereafter, or the electron transport layer, a 150 nm-thickaluminum electrode (cathode) was formed by vacuum deposition at adeposition rate of 1 nm/sec.

The thus-prepared organic EL device exhibited an EL spectrum showingλmax=625 nm and luminescent efficiencies of 1.5 lm/W at a luminance of100 cd/m².

EXAMPLE 21 Synthesis of Ex. Comp. No. 62

In a 2 liter-three-necked flask, 145.8 g (718 mM) of5-bromo-2-hydroxybenzyl alcohol, 246.5 g (718 mM) of triphenylphosphine.HBr, and 730 ml of acetonitrile were placed and refluxed understirring for 3 hours. The reaction liquid was cooled down to roomtemperature to precipitate a crystal of5-bromo-2-hydroxybenzyltriphenylphosphonium bromide (I), which wasrecovered by filtration (Yield: 362.0 g (95.5%)).

In a 1 liter-three-necked flask, 50.0 g (94.7 mM) o the phosphoniumbromide (I), 31.1 g (104 mM) of 1-nonanoic acid anhydride, 450 ml oftoluene and 39.6 g (392 mM) of triethylamine were placed and refluxedunder stirring for 6 hours. The reaction liquid was cooled down to roomtemperature to precipitate a crystal, which was filtered out. Thesolvent of the filtrate was distilled off under reduced pressure toobtain a residue. The residue was purified by silica gel columnchromatography (eluent: hexane) to a colorless oily product of2-octyl-5-bromobenzofuran (II) (Yield: 25.1 g (85.8%)).

In a 500 ml-three-necked flask, 19.0 g (61.5 mM) of2-octyl-5-bromobenzofuran (II) and 190 ml of anhydrous tetrahydrofuran(THF) were placed. To the mixture, 45 ml (72.0 mM) of 1.6M-n-butyllithium solution in hexane was added dropwise under argonstream at −70° C. or below in 30 min., followed by stirring at thattemperature for 4 hours. To the resultant mixture, a solution of 17.8 g(171 mM) of trimethylborate in 70 ml of anhydrous THF was added dropwiseat −70° C. or below in 20 min., and stirred at that temperature for 2hours. The system was heated up to room temperature and stirred for 17hours. To the reaction mixture, 100 ml of 10%-hydrochloric acid wasadded dropwise, followed by extraction with ether. The organic layer waswashed with water and dried with anhydrous sodium sulfate, followed bydistilling-off of the solvent under reduced pressure to obtain aresidue. The residue was purified by silica gel column chromatography(eluent: hexane/ethyl acetate=4/1) to obtain a white crystal of2-octylbenzofuran-5-boronic acid (III) (Yield: 10.8 g (64.1%)).

It is easy to synthesize the following compound in the same manner as inExample 1 except for using 2-octylbenzofuran-5-boronic acid (III)instead of 2-benzofuran boronic acid in Example 1.

Tris[2-(2-octylbenzofuran-5-yl)pyridine-C³,N]iridium (III).

EXAMPLE 22 Synthesis of Ex. Comp. No. 61

It is easy to synthesis the following compound in the same manner as inExample 1 except for using, instead of2-(5-trifluoromethylpyridine-2-yl)benzofuran,2-phenyl-5-(5-trifluoromethylpyridine-2-yl)benzofuran synthesized in thesame manner as in Example 21 except that 2-phenyl-5-bromobenzofuran wassynthesized from benzoic acid chloride used instead of 1-nonanoic acidand 2-phenyl-5-(5-trifluoromethyl-pyridine-2-yl)benzofuran wassynthesized from 2-phenyl-5-bromobenzofuran.

Tris[2-(2-phenylbenzofuran-5-yl)-5-trifluoro-methylpyridine-C³,N]iridium(III).

EXAMPLE 23 Synthesis of Ex. Comp. No. 72

4-bromo-2-hydroxybenzyl alcohol (IV) is synthesized from4-aminosalicylic acid (made by Aldrich Co.) in the following reactionscheme, and 4-bromo-2-hydroxybenzyltriphenylphosphon bromide (V) issynthesized in the same manner as in Example 21.

It is easy to synthesize the following compound in the same manner as inExample 21 except for using 1-butanoic acid anhydrate instead of1-nonanoic acid anhydrate in Example 21.

Tris[2-(2-propylbenzofuran-6-yl)pyridine-C⁵,N]iridium (III).

As described above, according-to the present invention, the metalcoordination compound of the formula (1) characterized by the benzofuranstructure of the formula (5) as a partial structure is an excellentmaterial which exhibits a high emission quantum efficiency. Theelectroluminescence device (luminescence device) of the presentinvention using, as a luminescent center material, the metalcoordination compound of the formula (1) is an excellent device whichnot only allows high-efficiency luminescence but also retains a highluminance for a long period and shows little deterioration by currentpassage. Further, the display apparatus using the electroluminescencedevice of the present invention exhibits excellent display performances.

1. A metal coordination compound represented by formula (1) below:ML_(m)L′L_(n)  (1), wherein M is a metal atom of Ir, Pt, Rh or Pd; L andL′ are mutually different bidentate ligands; m is 1, 2 or 3 and n is 0,1 or 2 with the proviso that m+n is 2 or 3; a partial structure MLm isrepresented by formula (2) shown below and a partial structure ML′_(n)is represented by formula (3) or (4) shown below:

wherein CyN1 and CyN2 are each cyclic group capable of having asubstituent, including a nitrogen atom and bonded to the metal atom Mvia the nitrogen atom; CyC1 and CyC2 are each cyclic group capable ofhaving a substituent, including a carbon atom and bonded to the metalatom M via the carbon atom with the proviso that the cyclic group CyN1and the cyclic group CyC1 are bonded to each other via a covalent bondand the cyclic group CyN2 and the cyclic group CyC2 are bonded to eachother via covalent bond; the optional substituent of the cyclic groupsis selected from a halogen atom, cyano group, a nitro group, atrialkylsilyl group of which the alkyl groups are independently a linearor branched alkyl group having 1 to 8 carbon-atoms, a linear or branchedalkyl group having 1 to 20 carbon atoms of which the alkyl group caninclude one or non-neighboring two or more methylene groups that can bereplaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C—, and thealkyl group can include a hydrogen atom that can be optionally replacedwith a fluorine atom, or an aromatic group capable of having asubstituent (that is a halogen atom, a cyano atom, a nitro atom, alinear or branched alkyl group having 1 to 20 carbon atoms of which thealkyl group can include one or non-neighboring two or more methylenegroups that can be replaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH—or —C≡C—, and the alkyl group can include a hydrogen atom that can beoptionally replaced with a fluorine atom); E and G are independently alinear or branched alkyl group having 1 to 20 carbon atoms of which thealkyl group can include a hydrogen atom that can be optionally replacedwith a fluorine atom, or an aromatic group capable of having asubstituent (that is a halogen atom, a cyano atom, a nitro atom, atrialkylsilyl group of which the alkyl groups are independently a linearor branched alkyl group having 1-8 carbon atoms, a linear or branchedalkyl group having 1 to 20 carbon atoms of which the alkyl group caninclude one or non-neighboring two or more methylene groups that can bereplaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C—, and thealkyl group can include a hydrogen atom that can be optionally replacedwith a fluorine atom; and at least one of the optional substituent(s) ofthe cyclic groups, and the cyclic groups CyC1 and CyC2 includes abenzofuran structure capable of having a substituent represented by thefollowing formula (5):

wherein the benzofuran structure of the formula (5) is bonded to CyN1,CyN2, CyC1 or CyC2 via a single bond at any one of 2- to 7-positionswhen the benzofuran structure is the optional substituent(s) of thecyclic groups, and the benzofuran structure of the formula (5) is bondedto CyN1 or CyN2 via a single bond at any one of 2- to 7-positions andbonded to the metal atom M via a single bond at any one of 2- to7-positions when the benzofuran structure is CyC1 or CyC2; the optionalsubstituent of the benzofuran structure of the formula (5) is selectedfrom a halogen atom, cyano group, a nitro group, a trialkylsilyl groupof which the alkyl groups are independently a linear or branched alkylgroup having 1 to 8 carbon atoms, a linear or branched alkyl grouphaving 1 to 20 carbon atoms of which the alkyl group can include one ornon-neighboring two or more methylene groups that can be replaced with—O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C—, and the alkyl groupcan include a hydrogen atom that can be optionally replaced with afluorine atom, or an aromatic group capable of having a substituent(that is a halogen atom, a cyano atom, a nitro atom, a linear orbranched alkyl group having 1 to 20 carbon atoms of which the alkylgroup can include one or non-neighboring two or more methylene groupsthat can be replaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or—C≡C—, and the alkyl group can include a hydrogen atom that can beoptionally replaced with a fluorine atom) with the proviso that anadjacent pair of substituents located at 4- to 7-positions of thebenzofuran structure of the formula (5) can be bonded to form a cyclicstructure.
 2. A metal coordination compound according to claim 1,wherein n is 0 in the formula (1).
 3. A metal coordination compoundaccording to claim 1, including a partial structure ML′_(n) representedby the formula (3) in the formula (1).
 4. A metal coordination compoundaccording to claim 1, including a partial structure ML′_(n) representedby the formula (4) in the formula (1).
 5. A metal coordination compoundaccording to claim 1, wherein the cyclic groups CyC1 and CyC2 areindependently selected from phenyl group, thienyl group, thianaphthylgroup, naphthyl group, pyrenyl group, 9-fluorenonyl group, fluorenylgroup, dibenzofuranyl group, dibenzothienyl group, carbazolyl group, orbenzofuranyl group, as an aromatic cyclic group capable of having asubstituent with the proviso that the aromatic cyclic group can includeone or two CH groups that can be replaced with a nitrogen atom.
 6. Ametal coordination compound according to claim 5, wherein the cyclicgroups CyC1 and Cy2 are independently phenyl group or benzofuranylgroup.
 7. A metal coordination compound according to claim 1, whereinthe cyclic groups CyN1 and CyN2 are independently selected from pyridylgroup, pyridazinyl group, and pyrimidinyl group, as an aromatic cyclicgroup capable of having a substituent.
 8. A metal coordination compoundaccording to claim 7, wherein the aromatic cyclic group is pyridylgroup.
 9. A metal coordination compound according to claim 1, whereinthe cyclic groups CyN1, CyN2, CyC1 and CyC2 are independentlynon-substituted, or have a substituent selected from a halogen atom anda linear or branched alkyl group having 1 to 20 carbon atoms, {of whichthe alkyl group can include one or non-neighboring two or more methylenegroups that can be replaced with —O—, —S—, —CO—, —CH═CH—, —C≡C—, or adivalent aromatic group capable of having a substituent (that is ahalogen atom or a linear or branched alkyl group having 1 to 20 carbonatoms (of which the alkyl group can include one or non-neighboring twoor more methylene groups that can be replaced with —O—, and the alkylgroup can include a hydrogen atom that can be optionally replaced with afluorine atom)), and the alkyl group can include a hydrogen atom thatcan be optionally replaced with a fluorine atom}.
 10. A metalcoordination compound according to claim 1, wherein M in the formula (1)is iridium.
 11. A metal coordination compound according to claim 1,which is represented by the following formula (6) or (7):

wherein R₁, R₂, R₃, R′₃ and R₄ are independently a hydrogen atom; afluorine atom; a linear or branched alkyl group of formula:C_(n)H_(2n+1)— in which n is an integer of 1-20, the alkyl group caninclude one or non-neighboring two or more methylene groups that can bereplaced with —O— and also can include a hydrogen atom that can beoptionally replaced with a fluorine atom; a phenyl group capable ofhaving a substituent; or a benzofuranyl group capable of having asubstituent; the optional substituent of phenyl group and benzofuranylgroup is a fluorine atom or a linear or branched alkyl group of formula:C_(n)H_(2n+1)— in which n is an integer of 1-20, the alkyl group caninclude one or non-neighboring two or more methylene groups that can bereplaced with —O— and also can include a hydrogen atom that can beoptionally replaced with a fluorine atom.
 12. An electroluminescencedevice, comprising: a pair of electrodes disposed on a substrate, and aluminescence unit comprising at least one organic compound disposedbetween the electrodes, wherein the organic compound comprises a metalcoordination compound represented by the formula (1) in claim
 1. 13. Anelectroluminescence device according to claim 12 wherein a voltage isapplied between the electrodes to emit phosphorescence.
 14. A picturedisplay apparatus, comprising an electroluminescence device according toclaim 12, and a means for supplying electric signals to theelectroluminescence device.